r(ouch) is just the radial distance from the black hole event horizon where the tidal accelerations between the center of your falling body to your head and center of you falling body to your feet would cause discomfort due to this tugging on your body. The reason I'm talking about a black hole is because this is a place in spacetime where the tidal effects would become strong enough to notice over a distance as small as the one meter between your waist to your head and the one meter between your waist and feet. There is no tidal effect on the center of your body because that is a free float frame. This was Einstein's great revelation when he discovered that the motion of a falling body in a gravitational field is equivalent to inertial motion in flat spacetime. The fact that you can evaluate the motion of freely falling 'ropes', (which are a distance away from you) as you fall, and that their motion reveals that there are tidal forces acting between you and the ropes as you both fall, reveals that the spacetime your in has curvature as determined by einstein's theory of General Relativity. This curvature reveals your are falling in a gravitational field. Tidal forces=curvature=gravity.
So far gravitons are strictly a theoretical idea. Yet I would be inclined to believe that they do exist and perform the function which string theory predicts. In that respect gravitons would=gravity.